Ramie

Ramie (/ˈreɪmi/, RAY-mee) is a flowering plant in the nettle family Urticaceae, native to eastern Asia. It is a herbaceous perennial growing to 1.0–2.5 m (3 ft 3 in–8 ft 2 in) tall; the leaves are heart-shaped, 7–15 cm (2.8–5.9 in) long and 6–12 cm (2.4–4.7 in) broad, and white on the underside with dense, small hairs—this gives it a silvery appearance; unlike stinging nettles, the hairs do not sting. The true ramie or China grass is also called Chinese plant or white ramie. A second type, known as green ramie or rhea, is believed to have originated in the Malay Peninsula. It has smaller leaves which are green on the underside, and it appears to be better suited to tropical conditions. The word 'ramie' is derived from the Malay word rami. Ramie is one of the oldest fiber crops, having been used for at least 6,000 years, and is principally used for fabric production. It is a bast fiber, and the fiber used for textiles comes from the inner bark (phloem) of the vegetative stalks and not the woody stem or outer bark. Ramie is normally harvested two to three times a year, but under good growing conditions can be harvested up to six times per year. Unlike other bast crops, ramie requires chemical processing to de-gum the fiber. When the plant begins flowering, or just before, it signals both a decline in growth and the plant being at its maximum fibre content, and is harvested. Stems are harvested by cutting just above the lateral roots or by bending the stem. This enables the core to be broken and the cortex can be stripped from the plant in situ. After harvesting, stems are decorticated while the plants are fresh. If this is not done while the plants are still fresh, the plants dry out and the bark will be difficult to remove. The bark ribbon is then dried as quickly as possible, preventing bacteria and fungi from attacking it. The dry weight of harvested stem from crops ranges from 3.4 to 4.5 t/ha/year. A 4.5-ton crop yields 1,600 kg/ha/year of dry undegummed fiber. The weight loss during degumming can be up to 25%, giving a yield of degummed fiber of about 1,200 kg/ha/year. The fiber extraction occurs in three stages. First, the cortex (bark) is removed; this can be done manually or by machine. This process is called decortication. Second, the cortex is scraped to remove most of the outer bark, the parenchyma in the bast layer and some of the gums and pectins. Third, the residual cortex material is washed, dried, and degummed to extract the spinnable fiber. Ramie has been grown in China for many centuries, and farmers in ancient China are known to have used the fiber to weave clothing. It may have been used in cloth for wrapping mummies in Egypt. Though ramie and flax are difficult to distinguish in ancient cloth, ramie's resistance to bacteria and mildew would make it appropriate for mummy wrapping.